CD52 and breast cancer: CD52, found in higher levels in metastatic breast cancer cells [both triple-negative breast cancer (TNBC) and non-TNBC], suppresses T-cell immunity by binding to the inhibitory ligand SIGLEC10, suggesting the potential for CD52-targeting therapies like alemtuzumab to reactivate T-cell immunity in metastatic thyroid or breast cancer (29, 30).